Problems with chugging and stalling 1976 280 Z

[FastWoman]

No idea about the whoosh.  I suggested a way of examining the issue from the hose that connects to your carbon canister -- somewhere in another thread.  I'd try that.  It could be that your vent is blocked (e.g. rusted closed) or incorrectly connected.  I suspect (and could easily be wrong) that the fault doesn't lie with the check valve.  Check valves usually go bad by failing to check, not by blocking off flow.

 

Perhaps you can give us some wire colors on those wires.  If they're black, they might have tiny little numbers printed in them every several inches.  You might have to clean them to see the numbers.  And if you're like me, you'll have to read them with your reading glasses.

 

Oh, if you have your car up on ramps, you might be able to have a look at the fuel tank vent line.  It runs from a fuel air separator to the side of the hatch area on the passenger side (which you won't be able to see), down into the space in front of the fuel tank, to that check valve (as I recall) and then to a metal line that should run to the engine compartment, then to a rubber hose that should lead to the carbon canister.  It would be interesting to know if you can pass air through the metal vent line.  (It should move freely.)

[Redwing]

Will do, thank you again for the help! I'll let you know. Son is busy today, maybe tomorrow after church. I am unable to carry anything heavy, especially in this heat. Index is to be 105 today. Ugh! Love my house AC.

[siteunseen]

Here's something about a resistor for the tach I found on atlanticz's Tech Tips.  It's not saying if it's by the ECU or the TIU though, but Fastwoman's right as usual. 

 

 

This is the original wiring on my 77 280z (Credits to Wayne Lewis!!!)

Notes:

• Red and Green carry trigger signal to ignition unit. (These will not be used)
• Blue wire to -neg post on ballast block will now go directly to -neg post on coil. (the small blue jumper wire can be discarded). This wire carries the ignition pulse to the ECU's pin 1 and it also goes to the tach after passing through a resistor (see pics above for ECU and resistor). The ECU triggers the injectors from this pulse.

[Patcon]

Redwing,

Be very careful under the car. Make sure the ramps are solid and the car is not gonna move. Set the emergency brake and block the wheels on the ground if you are unsure its not gonna move. We don't want you getting hurt before we educate you

[Redwing]

Awww, sweet of you to worry Patcon. Thank you. I would not have thought of chocking the back wheels.

A man here was working under his car the other day. He had it being held up by a fork lift. It slid off and killed him instantly. That was not too smart in my book.

News... RedZeee stopped on me today and this time would not start at all. I was about 10 acres away from home, baking in the heat. (Index was to be 105 today.) Anywayyyy, my neighbor came out and we did the try to start with the sparkplug causing a spark on metal. There was a spark then She did! Ran for about 5 sec, died and refused to start again. Neighbor then pulled us home.

[FastWoman]

What Patcon said!

 

So you say there was spark, but the engine wouldn't run longer than 5 sec?  That sounds like a fuel issue to me.  You should try the starter fluid test next time.  If the engine runs for a few sec on the starter fluid and then dies, that confirms the ignition is working and your fuel is not.  Probably the best place to shoot in some starter fluid is the connection from the back of the intake manifold to the brake booster line.  Disconnect the black hose that's about as big around as your finger.  Shoot a good blast of starter fluid into the intake manifold (maybe a 1 second shot).  Put the hose back.  (You don't need to tighten the clamp yet.)  And then without piddling around too long, crank the engine.  After you're done, don't forget to re-tighten the clamp on the brake booster line.

 

I sure would like to see a better photo of your engine.  The one you have is sort of small and fuzzy.  I'm seeing a few odd things that I can't quite decipher.  There's what appears to be an AC hose coming out below your throttle linkage and going to a dryer/accumulator on the driver side fender?  Nothing wrong with that, but different.  Then I see what appears to be two red, silicone rubber hoses feeding coolant to the block beneath the auxiliary air regulator (AAR).  I question whether that can hold pressure correctly, not being reinforced.  Then there's a vacuum line that seems to dive between your #5 and #6 intake runners -- probably not a good idea.  And then your fuel inejction rail seems to be turned at an odd angle.  Other things too.  It would be good to have a better look.

 

I'll have a look at your wiring photos too.  Give me a little while to study them...

[Redwing]

I have been unable to buy starter fluid to test this way. Have to wait until SS arrives on the 3rd.

But new happenings. In the morning, she only went to the mailbox (live in country, far away) did her chugging, stopped and refused to start again. Neighbor pulled her home again late in day, she still would not start. So, I believe that I cannot even try to drive again until somehow finding and fixing problem.

My neighbor, a real country boy jack of all trades, works on all his cars, says he believes it is the fuel pump. "That's how they go, giving some warning, then suddenly quit."

Not saying he is an expert, just wondering if any of this could be true. Being off the road totally is a great concern.

Any easy way to test fuel pump?

[Redwing]

Thank you Patcon, I will do as you and FastWoman suggested as soon as I get the starter fluid.

[FastWoman]

Your neighbor could be right.  That's how my fuel pump went -- similar to all that you have described.  The first time the engine died was in the middle of a 100 mi trip.  The second time it ran for 30 min.  The next few times maybe 15 min.  Then 10.

 

The way I tested my pump was to put a pressure gauge on a T-fitting inline between the fuel filter and fuel rail.  Then I removed the hose from the fuel return end of the rail, attached a long vinyl tube, and stuck the other end into the filler neck of the gas tank.  Then I hot-wired power to the fuel pump and ran it in the driveway, while watching pressure and flow rate (how fast fuel was ejected from the return and then pouring back into the tank.  I found that flow rate slowly dropped until there was no more return flow, and then the pressure started dropping from there.  I replaced the pump, and all was good.

 

Having said that, it's important that you actually test the pump before replacing it.  Parts are expensive, and OEM parts are diminishing in supply.  And the problem could easily be something else.  You should also look for rust in your tank, and you should confirm with the starter fluid that your ignition is still working when the car dies.  And you should also probably have a look at the fuel lines and vent system to see if everything looks good.  So you have some work yet.  But I do agree with your neighbor that a failing pump should be on your short-list of possible culprits.

[Redwing]

Thank you for your good advice. I am sure the fuel tank needs attention, but I have to save up the $300 before I can do it. Also, I know there are other problems. Perhaps I can manage to work on them while she is not running. So glad I do not have anymore Dr appointments till Sept.

I have been reading all sort of posts. On I read was someone complain about the chugging in 1st and 2nd gears. Sounds uncannily similar to my chugging.

I cannot find the posts that are important to read again and use. Any easy way to do so?

Battery almost dead, gotta go.

Thank you again!

[siteunseen]

I cannot find the posts that are important to read again and use. Any easy way to do so?

 

I copy the posts and paste them into an email to myself when I want to keep info I've read.  There's probably a better way I'm sure but that works and is quick.

[Patcon]

Or you can use the thread tools and subscribe to the threads that have good info in them.